This invention relates to a digital display with a stepping device which uses barrels for carrying the numbers, especially for a 24-hour display.
Digital 24-hour displays are already known in the art. Such displays are equipped, for example, with rotating disks running past a display window. Sometimes these displays are drop-leaf or tape displays. These known displays have the disadvantage that they are either difficult to manufacture and hence expensive, or that they require a lot of space. There are also known 24-hour displays which use barrels for carrying the numbers. Up to now, these 24-hour displays had the disadvantage that one could not optimize the ratio of the constructed number height to the barrel diameter, and hence the construction height of the digital display by means of a maximum number height and a minimum barrel size.
If the number height was made as large as desired, the barrel diameter and hence the construction height of the display became too large. If on the other hand, one preselected the construction height and hence the barrel diameter, the number height inscribable on the barrels become too small so that it could only be read with difficulty. In addition, such digital displays with barrels for bearing numbers mostly use a jack stepping device which has the disadvantage that the time display cannot be corrected in both directions, i.e., in the plus or minus direction.
Furthermore, these digital display barrels have the disadvantage that either at least 12 numbers must be accommodated on a barrel, or that, when accommodating less than 12 numbers on the barrel, expensive and still not reliably stepping reset mechanisms for the barrels had to be installed. Another disadvantage of known digital displays with digit barrels is that the number lettering is interrupted several times, e.g., by mask mountings located in front of the barrels so that definite and clear reading of the numbers is made difficult. These interruptions of the number lettering can be eliminated only by expensive and not always perfect auxiliary mechanisms.
Accordingly, it is an object of the present invention to provide an inexpensive digital display suitable for mass production and requiring little assembly effort and to improve the ratio of maximum number letter height to minimum construction height and hence a minimum barrel diameter. At the same time, it is the object of the present invention to reduce to a minimum the space requirement of the stepping device for the 24-hour display.
Another object of the present invention is to provide an arrangement of the foregoing character which is simple in design and may be readily fabricated.
A still further object of the present invention is to provide an arrangement, as described, which has a substantially long operating life and may be economically maintained in service.